C. Statistics and Research Design (STAT) Core Core Director: Domenic V. Cicchetti, Ph.D. Investigators: Alan Kazdin Ph.D., Marek Chawarski, Ph.D. I. OBJECTIVES The Statistics and Research Design (STAT) Core resource provides ongoing support for both methodological and data analytic strategies that apply to research investigations deriving from each of the three Program Project Areas. This is accomplished and reflected in biostatistical consultations on an individual and project basis as well as in presentations and publications. This task is facilitated in this program project grant by the ongoing collaborations of program project staff and personnel, their use of current, standard clinical instruments, as well as a common array of required standard and innovative data analytic strategies. With the regular meeting of project personnel data management and statistical analysis becomes an ongoing collaborative process both within as well as between the projects. This ongoing collaboration also serves to simplify the formalization of the required liaison between the STAT Core and the Assessment and Administrative Cores. The STAT Core of the Program Project is charged with the overall responsibility for assuring that investigators have access to, and make use of, high level consultation and collaboration from the planning stages of research projects through their final reporting in scientific publications. The major objectives of the STAT Core are to assure that research within each Program Project exemplifies: [unreadable] the highest quality of research design possible in a given clinical research application [unreadable] progressive biostatistical methodologies, computer programs, and data analytic techniques [unreadable] the evaluation of new methodologies and techniques as they emerge within the field, in order to both determine their potential usefulness for the Program Project, as well as to make them available to other investigators and in the broader scientific community [unreadable] the facilitation of collaboration and the coordination of data deriving from the various Project Areas, in order to determine areas of scientific knowledge that are pertinent across more than one Project (e.g., analysis of longitudinal data) [unreadable] the development and assessment of the psychometric properties of prevailing diagnostic instruments, as they are required to meet any given study objective [unreadable] the implementation of multivariate data analytic procedures as required to facilitate data analysis in a given Project Area [unreadable] consultation and discussions with both senior and junior Project investigators about specific research designs, methodologies, relevant computer programs, and interpretations of research findings and the sharing of knowledge about our ongoing research, and related research in the broader field, by semi-monthly presentations, using Power Point and other innovative technologies. These presentations serve multiple functions, including among them, the education of our junior staff;and preparation for both papers to be read at professional scientific meetings, and research publications;and for the smooth functioning and synergism of the three Cores (Administrative, Assessment, and Statistics and Research Design) that oversee each of the Program Projects. Toward this aim, participants include: Program Project Core Directors, P.l.s, and Senior and Junior staff, as well as investigators in related areas of inquiry (e.g., research in the genetics of autism and autism spectrum disorders). The latter presentations are made by internationally recognized scientists from within the greater Yale University community as well as from other parts of the country and abroad.